3D Printing-optimized Redesign Of A Suction Pad

Production tools are among the areas of application in which additive manufacturing (AF) can often fully demonstrate its strengths. A clear example of this is the redesign of a suction cup that lifts light, cylindrical objects in a series production system. The redesign, in which Materialize worked closely with the gripper user, resulted in several significant improvements. Among other things, the manufacturing costs per gripper were halved. The suction cup was originally designed in such a way that it could be manufactured entirely using conventional processes. For the necessary internal channels, several straight holes were drilled from different directions so that they were connected to each other. Openings were closed with blind plugs. In order not to further increase the component costs,further milling work to reduce the gripper volume was dispensed with.

Design freedom as a goal

The user of the gripper already had experience with the additive manufacturing of plastic parts and knew their advantages in terms of costs and efficiency, especially with production tools. Nevertheless, as with all redesign ideas, he first had to ask himself whether 3D printing would really be worthwhile with this production tool. A comparison of his requirements for the gripper with the possibilities of 3D printing led to a clear result: Lower manufacturing costs, lower weight, faster movements, shorter gripping cycles, better vacuum distribution and fewer leaks are all goals that can be achieved with AF and the associated design freedom.

In-house development not optimal

When choosing the material, the gripper user opted for aluminum. On the one hand, the metal is significantly more wear-resistant than plastic, and yet it is light. On the other hand, it enables smooth, easy-to-clean surfaces. This was important to him in order to be able to keep the gripper clean easily even while production was running. From an economic point of view, aluminum is also very well suited for small to medium-sized components with high value and small quantities. After the gripper user had developed a design for the AF himself, he contacted Materialize to have the component produced there. The team of experts from the 3D printing service provider and software manufacturer quickly realized that the design could still be improved. Although the existing construction already offered a significant weight reduction, the production costs were higher than the original production method and the internal channels of the suction pad were also not aerodynamically optimized.

No support structures inside

In consultation with the gripper user, Materialize's experts set about further optimizing the 3D printing design. For the redesign, they used the Siemens NX Realize Shape module, which enables free-form modeling. With the help of Materialize's Magics software, the experts also optimized the geometry depending on the printing process. To do this, they use a preview function that can display all the necessary support areas for a component in the selected component orientation. In this way, they were able to ensure that no support structures were required inside the component in order to print the walls that were growing together.

Picture gallery

The design team aligned the parts in the installation space in such a way that on the one hand the number of support structures required was further minimized and on the other hand the quality of the contact areas in the suction area was optimized. It was also very important that the new design ensured a homogeneous distribution of the vacuum at the suction points. The cylindrical body is thus taken up more reliably. The Materialize team of experts also reduced the lines of tension by making transitions between thin and thick material thicknesses slower, more fluid. This was important because tension lines not only negatively influence the external appearance, but also the mechanical properties.

Weight reduced to a minimum

In this way, the total volume and weight of the component were reduced to a necessary minimum. This has a direct impact on the material costs, since in 3D metal printing - unlike in the case of metal-cutting processes - unused material can largely be recovered and reused directly. Noteworthy costs only arise for the material that is actually required for the component and support structures. The small number of supports and their minimal contact area with the component in non-critical areas also have a positive effect on post-processing. As a result, the support structures can be removed without much time and effort. As a final step, only the threads had to be cut for assembly. Compared to the first 3D printing model, a further time and cost advantage was achieved: increasing the number of components per construction job from 28 to 46. The new component geometry enables a significantly more efficient arrangement on the construction platform, which is also positive Price per part affects.

Supplementary information on when 3D printing pays off

A key advantage of 3D printing is the ability to create complex structures at no additional cost. That means: Even if the process of additive metal production is usually more expensive than traditional processes, it does not matter how complex the component ultimately becomes in terms of costs. With appropriate knowledge and good planning, for example, solid material can be replaced by lattice structures without impairing the stability and functionality of a component.

3D printing is also a more cost-effective manufacturing method if the functionalities of a component are improved or expanded. Among other things, molds can be integrated into the component easily and without additional costs, which simplify assembly with other parts or which are advantageous in later use - such as mounting points or internal heat-dissipating ducts.

Additive manufacturing also offers a cost advantage compared to machining expensive materials: With additive manufacturing, the metal powder, which is not fused by laser during the printing process, can be almost completely recovered and used again for another manufacturing process.

Halved costs

A comparison of volume values and manufacturing costs between the original gripper, the first 3D print model and the final design shows the considerable progress that has been made: While the first 3D print model already had 79% less volume than the milled and drilled original gripper the gripper optimized by Materialize even only 6% of the volume of the original component. The cost per suction pad has been reduced from 300 euros for the traditional tool to 150 euros for the Materialize model. The first 3D print design of the gripper user would have been 6% more expensive to manufacture.

You might also be interested in:

Laser melting

Redesign of a Kruger valve hinge for additive manufacturing

3D printing software

Automatic creation of support structures for metal 3D printing

Book tip

Development and construction of components to be manufactured additively

SEMINAR TIP In the seminar "3D printing in direct digital production" of the engineering practice academy, the participants get to know different methods of professional 3D printing and get a comprehensive overview of the developments, possibilities and limits of this direct manufacturing technology.

Registration: www.b2bseminare.de/konstruction/3d-druck-in-der-direkten-digitalen-fertigung

Article files and article links

Link: To Materialize's additive manufacturing services